This paper presents a novel design for a modular snake-like robot with magnetic coupling between the modules. Each module combines 3D-printed mechanical parts with widely available standard electronic components, resulting in a highly customizable, low-cost robot platform for research and education. Since simulation and 3D-printing rely on the same model-files, the design also integrates smoothly into simulation environments like OpenRAVE. The robot can be assembled and re-assembled on the fly. Automatic topology detection is realized with custom connection-interfaces and dynamic initialization of intermodule communication.